Grading apparatus



Filed Jiine 17, 1941 w m n e r me O 3% 2 .mm m UV .0

Patented Dec. 22, 1942 iJNlTED GRADEING APPARATUS Eugen Geiss, Berlin-Charlottenburg, Germany,

assignor to General Electric Company, a corporation of New York Application June 17, 1941, Serial No. 398,503 r In Germany May 18, 1940 8 Claims.

My invention relates to a grading apparatus, and although not limited thereto it has application to an apparatus for classifying metal sheets atccording to their gage as they are sheared from 5 up.

In automatic testing and grading devices for rolled plates, the steel strip from which the plates are cut is usually tested by means of a thickness gage and is then cut into plates. and a steering device or switch which is controlled by the thickness gage eliminates those plates the thickness of which deviates from a prescribed thickness. The thickness gage is usually placed ahead ofthe shears in the sense of the rolling process or movement of the strip, since to place it to gage the individual plates after they have been sheared is impractical. Since the thickness gage and the sorting or deviating device for eliminating the plate with the incorrect thickness are placed comparatively far apart from each other, the plates will take a relatively long time to travel the distance between the measuring instrument and the deviation devices. In arrangements employed in the prior art, the deviating devices are controlled by the measuring apparatus through a time delay system which must necessarily operate very accurately in order that the correct deviating device may be opened at the right moment or closed at the right time. Since the speed of travel of the sheared plates may vary, when a 3.

time delay mechanism is employed, additional means must be employed for changing the constants of the time delay devices as a function of the rolling speed.

t is, therefore, an object of my invention to provide an improved arrangement for classifying metal sheets according to their gage.

Another object of my invention is to provide an improved device for classifying metal sheets which will deviate the sheets the thickness of which is in excess of the required thickness at one station, and which will deviate the sheets the thickness of which is under the normal or required thickness at another discharge station. 7

A further object of my invention is to provide an improved apparatus for controlling the movement of strip material in response to its thickness.

A still further object of my invention is to provide an improved grading apparatus.

Further objects and advantages of my invention will become apparent from the following description referring to the accompanying drawing, and the features of novelty which characterize larity in the claims annexed to and forming a part of this specification.

In the drawing the single figure illustrates a system for classifying metal sheets according to their thickness as they are sheared from strip, which system is provided with an embodiment of my invention.

In the arrangement illustrated in the drawing, I have provided a grading apparatus which includes an arrangement for measuring the thickness of a strip material and for producing a magnetic impression on any portion thereof the thickness of which deviates from a predetermined normal thickness. A trap is provided the operation of which is controlled in response to the presence or absence of the magnetic impression in order to deviate the sheet which has the non-normal thickness.

Referring more particularly to the drawing, I have illustrated my invention as applied to the grading of sheets or plates as they are cut from a strip material It as it is unwound from. a reel H. A plurality of power driven rolls l2 may be provided for moving the strip material ID towards a suitable shearing mechanism indicated generally by the numeral l3. In the arrangement illustrated in the drawing the shearing mechanism includes a pair ofknives [4 which are mounted on a pair of rolls l5. These rolls may be power driven and as the knives M are forced against the strip, the strip is cut. By controlling the movement of the shears the strip may be cut into sections or plates of any suitable lengths. The sheets are then moved along by any suitable arrangement, such as a power driven conveyor, power driven rollers or movable belt to a suitable stacking machine, not shown. On the conveyor before the sheets reach the stacking machine, I have provided a pair of traps indicated generally by the numerals l6 and I! which are operated by my improved control device so that the rolled plates which have a non-normal thickness may be removed in order that only the plates with the proper thickness may reach the stacking machine. The traps l6 and I! or deviating devices may be of any suitable construction and in the arrangement illustrated in the drawing, they are shown as movable door arrangements l8 and it which are operated by motors 20 and 2| through suitable linkage arrangements 22 and 23 respectively. The trap l6 operates when a plate has deviated the normal thickness in a one direction, such as being too thin, while the trap I! will operate if the plate thickness has become in my invention will be pointed out with particuexcess of a predetermined or normal thickness.

It is to be understood, however, that if desired only a single trap mechanism need be employed for removing the sheets the thickness of which is either above or below the normal thickness, without selectively removing the sheets as may be done by the control device illustrated.

In order that the traps l6 and I1 may be controlled in responseto the deviation in thickness of the strip material It] from a predetermined or normal thickness, I provide a, suitable gage device indicated generally by the numeral 24 for continuously gaging the strip material; It). The gaging device 24 may be of any suitable type and in the arrangement illustrated intheLdrawing-it is diagrammatically shownas ap'air of rollers 25 and 26, the roller 26 being mounted below the band in fixed bearings, whilethe roller -.25 is mounted above the band on movableibearings. 'I'h'esemeasuring rollers are continuously. pressed against the material, and the motion of'the upper measuring roll with respect to' the lower measuring roll represents the change ine-thickness of the strip material vabove or below a predetermined normal thickness. This motion of the ,upper. roll-may be transmitted to-a suitable control I .system in any suitable-manner,- andwin. the' arrangement illustrated in the drawing the 'roll '25 is 1 connected to an armature '21 of a;gage head'through a suitable linkagemech'anism T23. The armature 2? is: relativelymovable with:re-

spect to .a .pair of gage coils 2 9 i and 3 0 which-have cores sstationarily "mounted. with respecti-to :the --armature so that movement :of theiarmature will change athe; air. gaps .therebetween. coils; 29:,and I are connected. in :anyesuitable The gage conventional ybridge .circuit :having "balancing arms 3 and-32. ;The;bridge .circuit. is :energized at conjugate points 33 and 34 from .a;:suitable source of supply-indicated by .the numeralj35,

through a suitable transformer. 36. .Theopposite natingcurrent when one of the relays, such as -44-.is energized. The electromagnet or magnet head 52 is similarly provided with a core 56, a

-coil"5| which is suitable energized from a direct -current source and an alternating current coil 58 'which is connected to a source of alternating 'T'CllIIBIlt when the'relay 45 is energized. The di- .;rect;current coils 54 and 51 are constantly energized from the direct current source whenever the gaging apparatus is in operation, in order to secure a constant magnetization condition in that portion of the material which "passes under these heads. For'clarity sake the rolls 25 and; 26 and the gage. head 5| and 52 has'heen shown as longitudinally disposed. However, in an actual installation the measuring rolls and both the magnetic .heads 5| and 52 may be placed side by side'oralong the lateral axis of thestrip material lil, or along an axis perpendicular to its longitudinal axis or direction of movement. It'will, therefore, be seen that the two magnet heads 5| and 52 will-produce tracks of magnetization on the strip, each track being parallel with the'longitudinal axis ofthe strip, or in the arrangement illustrated in the. drawingparallel with thedirectionof .movement thereoi. Thus whenthe conjugate points are:connected;to;;a suitablezresponsive: meter/31 .through a rectifying device 38. "The meter -31 includes .arniicro-ammeter which has amovable..contact,:.39,ithe movement ofwhich. is: responsive to the zcurrentzwhiclrfiows from thebridge circuit to theammeter through the lines ifl andi4l. -Thetammeter'isialsozprovided' with stationary contacts 1 .42v and 343. A painof relays Hand-'45 are providedthe operating coils ofwhich are selectively .energizedzwhen "the movable contact 39 contacts the stationary contacts 42 or .43. Asuitable source of-supply 46, such as a battery may be connected to the movable contact39..and to operating: coils "4'| and 48. of the relays 4'4 and 45, respectively. The relay operating-coil-4T is-also connected-to the contact 42 while-the coil 48 is connected to theacontact 43.

It will,-therefore, be seen that when themovable contact 39' contactsthe contact, the" relay coil 41 will be energized to -close contacts-49 of the relay 44. Conversely, ifthe contactarm-38 cooperates with the contact 43, contacts 50 of the relay 45 will be closed. The measuring gagecircuit isso adjusted that the operatingarm '39 is in a zero or neutral position when the measuring rolls 25 and 25-are at a distance from-each other which corresponds with the desired ornormalthickness of the strip material I0. When' the material isin excessthe arm-39 will contact-43, while when the .material is too thin the arm will contact 42.

'In order toproduce a suitable electrical impression on the strip materialwhenwanysportion deviatesa predetermined amount from azsuitable normal thickness, which impression will inturn gage determines that the thickness ;of.;any portion of the. strip is too. small by a; predetermined amount,,the relay 44 will beenergizedyandzwill close thecontacts 49 in order toconncct the-coil '55 across a suitable alternating current source,

which in the drawing includes lines :59.and 60 of a three phase source which may be connected to lines 59,-60 and 6|. The circuit may be, traced from the line59 to conductor 62, contacts 45, conductor 63, coil 55, and conductor 64 to1line 6|]. The energizing of the coil will'zproduce a V pulsating magnetization characteristic which. 'is

a pulsating flux laterally spacedfromthe flux produced by the magnet headi5l. This'pulsating flux may inturn be employed to actuate a suitablecontrol device which will be described below. Of course, it is to be understood thatsince the rolls 25 and 26 and the gage .heads 5|. and 52 are in alignment in a lateral directionithe coils v55 and 56 will not be simultaneously energized.

In order to provide devices which may be responsive to the magnetic impressions which are put on any portion of the strip which deviates from the .normal thickness, I provide suitable scanning devices 61 and E8. 1The.scanning device G'Lincludes a suitable core 69.and..coil"|0. The: core '59 and coil'lfl'maybe mountedin a 'of a lever arm' H which is connected to the scanning device and to a stationary support 12. The scanning head 61 is also mounted for vertical movement so as to take care of any irregularity in the plates and it may also be adjusted so as to prevent it from moving any closer than a suitable minimum distance to the plates. The distance between the scanning head 61 and the deviating trap l6 may be approximately equal to the length of a plate section so as to permit a reliable grading of even such plates the thickness of which is incorrect only within the last part of the plate or shortly before its rear edge. The traps l6 and I! may be placed any suitable distance apart and the scanning head 68 is similarly constructed as ill, and is also placed a similar distance in front of its trap H. In addition to be longitudinally disposed the scanning heads 61 and 68 are also laterally disposed the same amount that the electromagnets and 52 are disposed. Thus, the scanning device 61 is so disposed with respect to the plates that the ends of the cores 69 will cut the flux which is produced by the gage head 5i. Also the scanning head 68 is so disposed with respect to the plate that it will cut the flux produced by the electromagnet 52. Thus, if the conveyor for moving the plates is run straight out from the shearing device and gage, it will be seen that the scanning head 6? will be in alignment with the electromagnet 5| while the scanning head be will be in alignment with the electromagnet 52. The scanning head 61 cooperates with a suitable control system for operating the motor 25 to open the trap l6 whenever any plate has a thickness which is less than a predetermined thickness, and the scanning head 68 cooperates with a suitable control system for operating the motor 2| for opening the trap ll whenever any plate has a thickness in excess of a predetermined amount. The control system for operating the motor 2| is similar to that which is employed to operate the motor 20 so only one is illustrated in the drawing and it will now be described.

The scanning head 61 operates to control the motor 26 in cooperation with a photoelectric cell 73 which is made conductive when a source of light Hi shines on the cathode thereof. The light source and photoelectric cell are placed on opposite sides of the path of movement of the plates so that the cell '13 will be made conductive during the interval of time when the rear end of one plate has passed by a predetermined point or out of the beam of light and until the front end of the next succeeding plate comes to that predetermined point and covers the light source. Thus, when there is a plate preventing the light source M from shining on the photoelectric tube l3, it will be nonconductive and between the time one plate moves out of the path of light and until the next plate moves into the path of light the tube 13 will be made conducting.

The motor 20 for operating the trap 15 may be of any suitable type and in the arrangement illustrated in the drawing it includes a three phase alternating current dynamo-electric machine, the rotor of which is connected across the three phase source of supply lines 5e, El], and 5! through conductors l5, l6 and Ta. The stator is also adapted to be connected across the same three phase line 59, 6B, and 6! through movable contacts 18 and 19 of relays and 8!, respectively. Thus, when the contacts 18 are closed the stator is connected through conductors 82, 83, and 84 and the contacts 18 in such a manner that the rotating field produced in the stator will be in phase with the rotating field produced in the rotor so that the rotor will assume a predetermined position with respect to the stator and no relatively rotation will be produced therebetween. With the contacts 18 of the relay 88 closed the motor is stationary and the trap is is closed. However, when the relay 89 is deenergized and its contacts 78 opened and the relay 3! is energized with its contacts 783 closed, the stator will be connected across the source of supply through the conductors 82, 83, 8 5 and the contact 19 in such a manner with respect to the rotor that a rotating field will be set up relative to the rotor so a torque is produced to rotate the rotor in such a direction so as to open the trap It. When the trap opens the rotor will have moved sufiiciently that the fields are again in phase. When the relay 8| is again deenergized so that the contacts 79 are open and the relay 80 is energized so that its contacts 18 are closed, a rotating field will be set up in the motor in an opposite direction which will cause the rotor to move in an opposite direction until the trap is again closed when the rotating fields in the rotor and stator are "again in synchronism or in phase, and the 'rotor will again be held in this position. Thus,

with the plates having a normal thickness the motor will be held in the closed position and the relay Silwill be energized and its contacts 18 closed through the control circuit which will now be described, while if the scanning head 61 finds a pulsating magnetic force which indicates that the thickness is too thin it will cooperate with the photoelectric cell to open the relay 8i! and close the relay 8! at a predetermined time with respect to the movement of the non-normal plate and hold the relays in this position for a suflicient length of time so that the non-normal plate may be deviated through the open trap [6. In like manner if the scanning head 88 cuts a pulsating flux it will cooperate with its photoelectric cell to operate the motor 2!. The scanning heads, however, will not be operated by the unidirectional flux.

The circuit through which the scanning head 67 and photoelectric cell 13 controls the operation of the motor relays 8B and 8! includes an electric discharge device indicated by the numeral 85, a relay the operation of which is controlled by the photoelectric cell 73, a relay 8! the operation of which is controlled by the relay 86 and, a relay 88 which is energized when the tube 85 is made conductive and the relay 86 is energized.

The electric discharge device 35 may be of any suitable typeand includes an anode 89, a cathode 90 which may be heated by a suitable heater 9| which may be energized from a suitablesource of power in a conventional manner, and a control electrode 92. The control electrode 92 is connected to the cathode 90 through a resistor 93 and a conductor 94 and this conductor is in turn connected to one side of the coil 10 of the scanning head 61 through a conductor 95. The other side of the coil 10 is connected to the control electrode 92 through a conductor 96 and a capacitor 91'. The capacitor 91 and resistor 93 are shunted by a resistor 98 and a capacitor 99. The cathode 9%! is connected: to the. negative. sideoi 2 alsuitable source .iof'power indicated by. thellinesfi Iv and I0 I through conductor 94, :and .a conductor I02. 'Thus when nocurrent isiflowingthrough thev coil .liithe potential on the control electrode will remain suificientlynegativeso 'as to prevent the tube fromifiring. ."l-lowever, the constants of. the circuit which is connected between the cathode andcontrol. electrode arelso proportioned that upon a'current' flowing through the coil I0 which is produced by the'core I69 of the gage head 6'! cutting the pulsating 'fiux on a portion of a sheet, the-potential of the control: electrode 92 will be raiseda sufficient amount with respect to the potential of the vcathoderellsothat current may be allowedto fiow'between the'anode 89.- and the cathode 90. ,Theianode S3 isconnected'to the positive line |0l .through a conductor I03, a resistor Hi l-and conductor I05. :Therelaytfiis energizedthrough its operatingcoil I06 when the;

photoelectric tube I3 is made'conductive. The operating circuit for the coil I06 may be'traced from the positive .side of the'D.-C. source IOI, conductor I03, coil I06, a :conductor I01; to the anode of the photoelectric cell through the cell to the cathode, conductor I08, and conductors?) and I02 toline I00. The relay I05 has contacts 109 which are closed when the relay is vdeenergized'and contactsl I0 which close When the operating coil I06 is energized. The contacts I09 1 are connected in circuit with an operating coil I I6 :are provided in .a'holding circuit forthe relay.

8| and the contacts I I! are provided in a holding circuit for .anenergizing coil 'IIB' for the relay 88. ."lhe'energi'zing circuit for the operating coil II8 'for'the relay BS'maybe traced from the line ltll, conductors'll2,'ll3,'a conductor H3, 6011 -II8, conductorI20,'the contacts III] which are closed when the r'elay'86 is'energized, the electricfdischarge tube 85; and the conductor" I02 to the line. I00. The'holding circuit for thecoil I I8 which is independent: of the discharge device 85 may be traced through the contacts II! which are closed when the relay- 81 is deenergized, a conductor I2I,tcon-tacts I22 .of the relay-'88 which are closed when the relay is energized, and a condu'ctor'l23 to the line Hi0. also provided with-contacts I24 which also close when the relay-88 is energizedand contacts I25 which are closed whenthe relay-. is 'deenergized. The latter contacts are' in circuit with an energizing coil I26'0f the motor relay 80, and-this circuit may be traced from the line IOI, conductor II2, relay operating coil I26, a conductor-I21, contacts I281 of the relay-"BI, these contacts'being closed when the latter relay is deenergized, a conductor I29, contact I25, and a conductor I23 to the line 190. 'The actuating circuit-for the motor relay SI includes an operating coil I30, one side of which is connected to the line IOI through a conductor I3I, conductor I32, contacts I33 which are on the relay 'all'and' which are closed when the relay is deenergized, conductor I34; contacts I24 which close when the relay 88 is energized, and conductor I23 to the line- I00. A holding circuit for" the'relay -8I independent of the relay- 88 is provided which includes the contacts The relay 08 is ELL' 5 I33. of the relay'80, a conductor. I35, contact. I36 Offthe relay 8| which are closed whenrthe relay :is energized, a conductor I31, contacts Il6'of the relay 8! which are closed when the relay. is energized, and conductor I23 to the line I00.

The operation of my improved gaging apparatus will now be described. Let us assumethat a. correct plate A occupies at a predetermined -momenta. position on the trap I'Gzin such away that it'covers the light source so that it cannot shine on the photoelectric cell 13. Let us also assume that a plate B is passing under the scanning .device 61. Let us also assumexthat at any suitable portion of the plateB' was gaged to be too thin so that a pulsating magnetization characteristic was impressed at that portion oithe plate B. When this portion comes under the scanning head 61 the two ends of the core 89 vwill be electrodynamically affected by thispulseating magnetization force, or a field'of varyin intensity will be cut by thecore so as to induce a current in the coil 10. It is who assumed that no current will be induced in the'coil I0 when the core 69 :is being cut by a field of constant intensity. The current now through the rready been broughtout, when the trap I6 is in a closed position the relay is energized through a circuit which includes the contact I25 of the relay 88 so that the armature ofthe'motor 20 will be held in its stationary position. With the scanning head 61 having been affected by the pulsating flux on a portion of the plate B the tube has been made conducting and when the plate A has moved so that its rear edge has just passed out of the path of light between the light source 14 and the photoelectric cell 13, the cell will be made conductive. Thus, when the photoelectric cell 13 is made conductive at the same time that the tube 85 is conductive the relay '80 will be de- -energized and the relay 8| will-be energized .so as to so connect the stator of the motor 20-so that a rotating field will be present in order to cause'it to rotate and'move'the trap I 6 to an open position. It is to be understood that the lightsource and photoelectric cell are-so placed relative to the trap that when the plate A moves out of the path of the light source, it will have also moved a suflicient amount off the trap I6 'sothat it will 'not'bedeviated by the trap when it opens but will pass along tobe scanned by the scanner 68.

With the trap l6 having been opened the plate B will be deviated from the normal path of movement along the conveyor or belt to a station which receives the plates, any portionof which are too thin. The circuits for accomplishing the deenergization of the relay 80 and the energization of the relay8l will now be traced. The photoelectric cell 13 having been made conductive completes the circuit for energizing'the coil I06 of the relay 86 so that its .normally closed contacts I 09 will be opened and its contacts III] closed. The opening of thecontacts I09 will deenergize therelayBI the function of relay 8|. Since current cannot flow through the which will become apparent as this description proceeds. With the contacts IIO closed and the tube 85 made conducting a circuit will be completed for energizing the relay 88. This circuit may be traced from the line IOI, conductors H2, H3, and H9, coil H8, conductor I20, contacts H0, conductor I05, tube 85, conductors 94 and I02 to the line I00. The energization of relay 88 opens its contacts I25 which deenergizes the relay 00, the energizing circuit for the relay 8!? being from the line IOI, coil I28, contact I28 through the contacts I25 to the line I00. The energization of the relay 88 also closes contacts I24 which with contacts I33 of the relay 80 closes the energizing circuit for the relay 8|. This circuit may be traced from the line IOI, conductor I3I, energizing coil I30, conductor I32, contacts I33, conductor I34, contacts I24, conductor I23 to the line I00. At the same, time the contacts I22 close a holding circuit for the relay 88 which is independent of the tube 85. This circuit may be traced from th line IOI, conductors H2, H3, and H9, coil H8, contacts H! on the relay 81 which contacts are closed since the relay 8'! has been deenergized by the movement of the relay 86 to an energized position, conductor I2I, contacts I22, conductor I23, to the line I00. The same contacts I22 which complete the holding circuit for the relay 88 also connect the anode of the tube 85 to the negative side of the line in order to deenergize the tube. This circuit may be traced from the line I00, conductor I23, contacts I22, conductor I2I, contacts I", conductor I20, contacts H which are closed since the relay 85 is energized, to the anode 89. This will prepare the tube to again be energized whenever a pulsating field is found on another plate.

When the plate B moves on to the trap so that its front end passes across the path of the light source to the photoelectric cell I3, the cell will be made non-conductive and the relay 85 will be deenergized, so that its contacts III) will be opened and its contacts I09 closed. The closing of contacts I09 will again energize the relay 8? which will cause its contacts H! to open and its contacts M6 to close. The opening of the contacts III will break the holding circuit for the relay 8B and cause it to move to its deenergized position which will cause its contacts I24 to open so as to disconnect the circuit including these contacts from the operating coil I30 of the relay SI. The relay 8i, however, will not drop out since the moving of the relay 8! to a circuit closing position closes its contacts H6 which closes a second holding circuit for the relay 8|, which may be traced from the line I M, conductor I3I, coil I30, conductor I32, contacts I33, con

ductor I35, contacts I88 which are closed since the relay 0| is energized, conductor I31, contacts H0, conductor I23 to the line I00. Thus, so long as the plate 13 remains between the light source I4 and the photoelectric cell 13 the relay 8i will remain energized through the last traced circuit. During the time the plate B is moving into the trap I 5 so as to be deviated thereby, a plate C will be scanned by the scanner 8?, and let us assume that the plate C has a normal thickness so that it will not energize the scanner. Therefore, when the plate B moves out of the path of the light source the relay 05 will become energized which will open the contacts I09 and close the contacts H0. The opening of the contacts I09 will deenergize the relay 8? which opens the contube 85, the relay 88 will not beenergized and with the relay 8I being deenergized the energizing circuit for the coil I26 of the relay 80 is again closed through the contacts I28 and the contacts I of the relay 88. This causes the armature of the motor to move so as to close the trap I5. If, however, the plate C had had a portion which was too thin the scanning device would have energized the tube 85 so that another circuit including the contacts I24 of the relay 88 so that the relay 8I would haveremained energized.

In view of the'foregoing, it will be seen that I have provided an improved grading apparatus .for gaging strip material before it is cut into :magnetic impressions, I am able to control detacts H6 which opens the holding circuit for the viating traps for controlling the destination of the sheets, the thickness of which deviates from the normal thickness. Instead of producing a magnetic impression on one track if the thickness is too thin and on another track laterally I thestrip were too thin, and the-other would be energized from a source of a difierent frequency if the strip were too thick. If desired, only one coil need be employed which could be selectively connected to the diiferent sources. If magnetic impressions of different frequency were employed, the scanning devices could be employed and with suitably designed filter circuits the electric discharge device could be energized whenever the frequency coordinated-with them would occur. Thus, the scanning heads 51 and 68 could be in longitudinal alignment so that if one frequency were present the scanning head 91 would energize its tube while if a difierent frequency were present the scanning head 58 would energize its tube so as to control the operation of the motor 2|. It is also to be understood that instead of producing two magnetic impressions onthestrip for under and over thickness, I may produce any suitable number of impressions on the strip and with cooperating heads and deviat ing devices I may selectively remove the nonnormal sheets at several stations according to their gage. This would dispense with the sorting of the non-normal sheets. It is also to be understood that instead of impressing a magnetic impression on the strip when the thickness of which deviates from a normal thickness, any other suitable electrical impression may be placed on the strip, which impression may be employed to control a suitable scanning device.

Although I have shown and described particular embodiments of my invention, I do not desire to be limited to the particular embodiments described, and I intend in the appended claims to cover all modifications which do not depart from the spirit and scope of my-invention.

What I claim as new and desire to secure by' Letters Patent of the-United States is;

1. In an apparatus for classifying metal sheets as they are sheared from strip, means for con tinuously magnetizing a strip of metal and for varying the magnetization of any portion the thickness of which deviates from a predetermined normal thickness, means for shearing the strip into sheets, and means responsive to the presence of said varied magnetization on a portion of any ofthe plates for deviating said non-normal sheets from said. normal sheets.

2. In an apparatus for classifying metal sheets as they. are sheared from strip, means for continuously magnetizing. a strip of metal with a unidirectional flux and, for superimposing a pulsating flux on said magnetized portion upon thethickness of. that portion deviating from a predetermined normal thickness, means for shearing the stripinto, sheets, and means responsiveto the pulsating character of said magnetization one. portionof any of the plates for deviating said non-normal sheetsfrom said normal sheets.

3. In an apparatus for classifying metal sheets as they areshearedrfrom strip, an electromagnet for. continuously magnetizing said strip, said electromagnet beingadapted. to be continuously excited from a, D.-C. source, means for continuously; measuring the thickness of the strip and for connecting, said electromagnet with an A.-C. source-when the thickness deviates from a predetermined'normal, and means responsive to the presence of the varying magnetization on a portion-ofany of the platesfor deviating said non-normal plates.

4. In an apparatus for classifying, metal sheets as they are sheared .from strip, an electromagnet havinga pair of coils, one of said coils being adapted to be connected to a, D.-C. source for continuously magnetizing said strip, means for continuously measuring the thickness of said strip and for connecting said second coil to an A.-C. source when the thickness deviates from a predetermined normal, and means responsive to the presence of the alternating magneticimpression on a portion of any, of the plates for deviatingsaid non-normal plates.

5. In an apparatus for classifying continuously moving metal sheets as they are sheared from strip, a pair of electromagnets disposed .to magnetize said strip in separate planes, each being parallel to the direction of movement, of said sheets, means for continuously measuring the thickness of said strip. and forenergizing one electromagnet if the thickness is in excess and for energizing the second of said electromagnets if the thickness is less than a predetermined normal thickness, and a pair of magnetic responsive means beingdisposed so thatone is responsive to magnetic impressions produced by said first electromagnet and said second magnetic responsive means is responsive to magnetic impressions produced by-said second electromagnet, and means being operative upon said first or said second magnetic responsive means being energized for distributing said sheared sheets to a plurality of discharge stations according to the gage of said sheets.

6. In an apparatus for classifying continuously moving metal sheets as-they are sheared, from strip, means for continuously measuring the strip and-for-producing a magnetic impression on a portion which deviates from a predetermined normal value, means disposed in the path of movement of said sheets and responsive to the presence of said magnetic impressions, means including an electric. motor operative to deviate a non-normal sheet, alight source disposed to producea ray of light across the path of movementof said sheets, a photoelectric cell operative'upon said 'light shining on its cathode, and, control means-responsiveato energization of said. magnetic responsive means; and said photoelectric cell for energizingsaid-motor. I

7. In an apparatus .ior classifying continuously movingsmetal sheets-as they are sheared from strip, eans for continuously measuring thestrip and, for 1 producing a magnetic impression on a portion ,whichdeviates from a predetermined normal value,,means disppsedin the pathof movement of said=sheets and responsive to the presence of said'magnetic impressions, a deviating-trap, an electric -motor operatively'connected to said trap, apair of motor relays adapted to be selectively energized to'control the rotation of saidimotor to operate said trap to adeviating or a closed position, a light source disposed to produce a rayof light across the-path of movement of said sheets, a photoelectric cell operative upon said light 'shiningon its cathode, said light source and cell being, so disposed with respect to said trap that the beam oflight is uncoveredupon the sheet infrontiof said non-normal sheet moving ofi said, trap; and-control means responsive to energization of said magnetic responsive means and saidphotoelectric cell for energizing one of said motorrelays for rotatingsaid motor to open saidi trap.

8. In anapparatusforclassifying continuously moving metal sheets as they; are sheared from strip, means for -continuously;measuring the strip and for;producing:amagnetic impression on a portionyvhich deviatesfrom a, predetermined normal value, means, disposedin the path of movementor": said sheets ,and responsive to the presence of saidpmagn'etic':impressions, an electric motor'operatively connected to said trap, a pair of motor relays adapted'to beselectively energized to control the rotation of said motor to operate said trap to a deviating or a closed position, a light source disposed to produce a ray of light across the path of movement of said sheets, a photoelectric. cell operative upon said light shining on its .cathode, said light source and cell being so disposed with respect to said trap that the beam of light is uncovered upon the sheet in front of said non-normal sheet moving oil said trap, an electricdischarge device adapted to be rendered; conductive upon energization of said magnetic responsive means, a first relay adapted to be energized upon energization of said photoelectric cell, a second relay having contacts adapted to: close a. circuit to energize one of said motor-relays tohold said trap closed when said second relayis deenergized, said first relay upon being energized beingradapted to close contacts to energize said second relay to deenergize said first motor relay and energize said second motor relay to, open saidtrap, said light source being covered to deenergizesaid cell and said first relay upon said non-normal sheet moving on said trap, and a third relay being adapted to be energized and have contacts closed, when said first-mentioned relay is deenergized to provide a holding circuit for said second motor relay, said cell being operative when said non-normal sheet moves out of the-path of said light source to cause said first relay to operate and deenergize said third relay to deenergize said second motor I relay.

EUGEN GEISS. 

